[PATCH v14 09/18] vmscan: move call to shrink_slab() to shrink_zones()

Vladimir Davydov
2013-12-16T12:24:37Z

This reduces the indentation level of do_try_to_free_pages() and removes
extra loop over all eligible zones counting the number of on-LRU pages.

Signed-off-by: Vladimir Davydov <vdavydov@parallels.com>
Reviewed-by: Glauber Costa <glommer@openvz.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Rik van Riel <riel@redhat.com>
---
mm/vmscan.c | 57 ++++++++++++++++++++++++++-------------------------------
1 file changed, 26 insertions(+), 31 deletions(-)

diff --git a/mm/vmscan.c b/mm/vmscan.c
index eea668d..035ab3a 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -2273,13 +2273,17 @@ static inline bool compaction_ready(struct zone *zone, struct scan_control *sc)
* the caller that it should consider retrying the allocation instead of
* further reclaim.
*/
-static bool shrink_zones(struct zonelist *zonelist, struct scan_control *sc)
+static bool shrink_zones(struct zonelist *zonelist,
+ struct scan_control *sc,
+ struct shrink_control *shrink)
{
struct zoneref *z;
struct zone *zone;
unsigned long nr_soft_reclaimed;
unsigned long nr_soft_scanned;
+ unsigned long lru_pages = 0;
bool aborted_reclaim = false;
+ struct reclaim_state *reclaim_state = current->reclaim_state;

/*
* If the number of buffer_heads in the machine exceeds the maximum
@@ -2289,6 +2293,8 @@ static bool shrink_zones(struct zonelist *zonelist, struct scan_control *sc)
if (buffer_heads_over_limit)
sc->gfp_mask |= __GFP_HIGHMEM;

+ nodes_clear(shrink->nodes_to_scan);
+
for_each_zone_zonelist_nodemask(zone, z, zonelist,
gfp_zone(sc->gfp_mask), sc->nodemask) {
if (!populated_zone(zone))
@@ -2300,6 +2306,10 @@ static bool shrink_zones(struct zonelist *zonelist, struct scan_control *sc)
if (global_reclaim(sc)) {
if (!cpuset_zone_allowed_hardwall(zone, GFP_KERNEL))
continue;
+
+ lru_pages += zone_reclaimable_pages(zone);
+ node_set(zone_to_nid(zone), shrink->nodes_to_scan);
+
if (sc->priority != DEF_PRIORITY &&
!zone_reclaimable(zone))
continue; /* Let kswapd poll it */
@@ -2336,6 +2346,20 @@ static bool shrink_zones(struct zonelist *zonelist, struct scan_control *sc)
shrink_zone(zone, sc);
}

+ /*
+ * Don't shrink slabs when reclaiming memory from over limit
+ * cgroups but do shrink slab at least once when aborting
+ * reclaim for compaction to avoid unevenly scanning file/anon
+ * LRU pages over slab pages.
+ */
+ if (global_reclaim(sc)) {
+ shrink_slab(shrink, sc->nr_scanned, lru_pages);
+ if (reclaim_state) {
+ sc->nr_reclaimed += reclaim_state->reclaimed_slab;
+ reclaim_state->reclaimed_slab = 0;
+ }
+ }
+
return aborted_reclaim;
}

@@ -2380,9 +2404,6 @@ static unsigned long do_try_to_free_pages(struct zonelist *zonelist,
struct shrink_control *shrink)
{
unsigned long total_scanned = 0;
- struct reclaim_state *reclaim_state = current->reclaim_state;
- struct zoneref *z;
- struct zone *zone;
unsigned long writeback_threshold;
bool aborted_reclaim;

@@ -2395,34 +2416,8 @@ static unsigned long do_try_to_free_pages(struct zonelist *zonelist,
vmpressure_prio(sc->gfp_mask, sc->target_mem_cgroup,
sc->priority);
sc->nr_scanned = 0;
- aborted_reclaim = shrink_zones(zonelist, sc);
-
- /*
- * Don't shrink slabs when reclaiming memory from over limit
- * cgroups but do shrink slab at least once when aborting
- * reclaim for compaction to avoid unevenly scanning file/anon
- * LRU pages over slab pages.
- */
- if (global_reclaim(sc)) {
- unsigned long lru_pages = 0;
+ aborted_reclaim = shrink_zones(zonelist, sc, shrink);

- nodes_clear(shrink->nodes_to_scan);
- for_each_zone_zonelist(zone, z, zonelist,
- gfp_zone(sc->gfp_mask)) {
- if (!cpuset_zone_allowed_hardwall(zone, GFP_KERNEL))
- continue;
-
- lru_pages += zone_reclaimable_pages(zone);
- node_set(zone_to_nid(zone),
- shrink->nodes_to_scan);
- }
-
- shrink_slab(shrink, sc->nr_scanned, lru_pages);
- if (reclaim_state) {
- sc->nr_reclaimed += reclaim_state->reclaimed_slab;
- reclaim_state->reclaimed_slab = 0;
- }
- }
total_scanned += sc->nr_scanned;
if (sc->nr_reclaimed >= sc->nr_to_reclaim)
goto out;
--
1.7.10.4